What Yahoo API or API's are legally allowed to be used in commercial(paid) software.

HI there,

I am sure this has been asked before. I have been developing an paid app that displays quotes values for the various indexes/companies.I don't need a real time data, this is just a dashboard.
What Yahoo API or API's are legally allowed to be used in such apps?
For Instance:
http://query.yahooapis.com/v1/public/yql